I dig the 70s spacey synthy stuff, so here are a few from the top of my head:
Rush 2112 - the intro is more like 1:30, but still
Steve Miller Band Threshold/Jet Airliner - ditto
Steve Miller Band Space Intro/Fly Like an Eagle - a little over a minute of bliss
The Who Baba O'riley
2112? DING DING DING! we have a winner!